Appointment in Samarra, John O'Hara's debut novel, is situated in the small Pennsylvania town of Gibbsville, a fictional place whose occupants and mores mirror those of O'Hara's hometown of Pottsville, Pennsylvania. Appointment centers around the self-destruction of one of the town's more popular gentlemen, Julian English. Told from the viewpoints of several different characters, Appointment in Samarra is also a novel of manners in that it depicts the way in which one must abide by certain rules in order to gain acceptance or maintain one's social standing. While many seemingly scandalous foibles are often overlooked, a much smaller infraction could be perceived as completely unacceptable and topple the entire social order of Gibbsville's elite, letting unspoken truths and feelings rise to the surface.

Details abound of Julian's tenuous marriage, as well as his vulnerable financial situation; both are themes that were prominent in O'Hara's own personal life as he wrote Appointment in Samarra on the heels of his own failed first marriage. Furthermore, O'Hara was often subject to financial pressures as he had a great deal of trouble holding a job. The novel's main character, Julian, is also a rather heavy drinker, which closely mirrors O'Hara's own patterns of drinking to the point of excess.

The most critically acclaimed of all his works, Appointment in Samarra was an instant success, earning O'Hara popularity with the general public and critical praise for his ear for dialogue and his attention to detail. Ironically, the things that earned Appointment in Samarra accolades upon its publication are the very things that wrought harsher criticism of his subsequent works, according to Fran Lebowitz in her introduction to the 1994 edition of the novel. She writes, "[Appointment in Samarra] is the [book] generally considered to be his best, particularly by his detractors who tend rather showily to concede it and who almost invariably employ its virtues as a weapon with which to smite the rest of his work."